For a long time foodstuffs, whether foodstuffs for human consumption or also animal feed products, have been preserved by being stored either in a can or in a glass jar closed with a lid. However, these packaging systems have some serious disadvantages, inter alia the high intrinsic weight, the energy-intensive production and the troublesome opening.
Alternative packaging systems for storing foodstuffs for a long period of time as far as possible without impairment are known from the prior art. These are containers produced from sheetlike composites—often also called laminate. Such sheetlike composites are often built up from a layer of thermoplastic, a carrier layer usually made of cardboard or paper, an adhesion promoter layer, an aluminium layer and a further layer of plastic. Such a sheetlike composite is disclosed, inter alia, in WO 90/09926. Such laminated containers already have many advantages over the conventional glass jars and cans, for example space-saving storage and low intrinsic weight. Nevertheless, possibilities for improvement also exist for these packaging systems.
In regions of the sheetlike composites which are exposed to high mechanical stresses during production of the container, in particular if barrier layers of aluminium foil are employed, the formation of small defects, such as cracks, fractures, blisters or non-sealed pockets or microchannels up to leaks, thus occurs again and again. Germs can be deposited in such defects, or even penetrate into the containers, as a result of which the foodstuff in the container may decay more easily. Any damage to the barrier layer furthermore leads to trouble spots in respect of entry of oxygen into the container, which in turn leads to losses in the quality of the foodstuff and also to a shortened shelf life. Regions which contain scores or folded edges or weaknesses in the sheetlike composite are particularly at risk, especially those regions which have scored crosses and are folded particular severely or in several dimensions during production of the container.